Biblio

The concept of Internet of Things (IoT) has received considerable attention and development in recent years. There have been significant studies on access control models for IoT in academia, while companies have already deployed several cloud-enabled IoT platforms. However, there is no consensus on a formal access control model for cloud-enabled IoT. The access-control oriented (ACO) architecture was recently proposed for cloud-enabled IoT, with virtual objects (VOs) and cloud services in the middle layers. Building upon ACO, operational and administrative access control models have been published for virtual object communication in cloud-enabled IoT illustrated by a use case of sensing speeding cars as a running example. In this paper, we study AWS IoT as a major commercial cloud-IoT platform and investigate its suitability for implementing the afore-mentioned academic models of ACO and VO communication control. While AWS IoT has a notion of digital shadows closely analogous to VOs, it lacks explicit capability for VO communication and thereby for VO communication control. Thus there is a significant mismatch between AWS IoT and these academic models. The principal contribution of this paper is to reconcile this mismatch by showing how to use the mechanisms of AWS IoT to effectively implement VO communication models. To this end, we develop an access control model for virtual objects (shadows) communication in AWS IoT called AWS-IoT-ACMVO. We develop a proof-of-concept implementation of the speeding cars use case in AWS IoT under guidance of this model, and provide selected performance measurements. We conclude with a discussion of possible alternate implementations of this use case in AWS IoT.

Attribute-Based Access Control (ABAC) has received significant attention in recent years, although the concept has been around for over two decades now. Many ABAC models, with different variations, have been proposed and formalized. Besides basic ABAC models, there are models designed with additional capabilities such as group attributes, group and attribute hierarchies and so on. Hierarchical relationship among groups and attributes enhances access control flexibility and facilitates attribute management and administration. However, implementation and demonstration of ABAC models in real-world applications is still lacking. In this paper, we present a restricted HGABAC (rHGABAC) model with user and object groups and group hierarchy. We then introduce attribute hierarchies in this model. We also present an authorization architecture for implementing rHGABAC utilizing the NIST Policy Machine (PM). PM allows to define attribute-based access control policies, however, the attributes in PM are different in nature than attributes in typical ABAC models as name-value pairs. We identify a policy configuration mechanism for our proposed model employing PM capabilities, and demonstrate use cases and their configuration and implementation in PM using our authorization architecture.